This invention generally pertains to locking assemblies. More specifically, the present invention relates to a locking assembly for locking a multi-sided member in a particular rotated orientation relative to a rigid body. The invention is particularly applicable to locking a bonnet or packing nut in a predetermined, threadedly installed relation to a valve body and will be described with reference thereto. However, it will be appreciated by those skilled in the art that the invention has broader application and may be adapted to use in many other environments as well.
With regard to valves, a compressive force on the sealing medium interposed between the valve body and the valve bonnet or packing nut is required to prevent leakage of system fluid through the mating threads between the valve body and the bonnet. The bonnet must be adjusted to a final position in the valve body so that the innermost end thereof exerts a desired compressive force against the sealing medium. Once a final adjustment position has been obtained, it is desirable to retain the bonnet in that position with some assurance that it will not be moved or rotated therefrom. Any relieving of the compressive force on the sealing medium would promote fluid leakage out of the valve past the above noted mating threads. Even more serious however, is the fact that excessive rotation of the bonnet could weaken the threaded interconnection with the valve body to such an extent that the bonnet could be forcibly ejected from association with the body by the pressure of the system fluid.
Accordingly, locking brackets have been utilized to retain the desired threaded interconnection between the bonnet and valve body. These prior locking brackets have, however, been generally configured so that when the bonnet was rotated to a final adjusted position, the locking bracket would overhang the valve body and thereby render it possible for clothing, tools, equipment and the like to catch thereon, and to cause injury or damage to the valve. Moreover, due to the specifics of the prior locking bracket designs, they were not adjustable to the extent required for providing a full range of locking positions for the associated bonnet. Also, such locking bracket designs necessitated the use of a fastener which penetrated the valve body for attachment purposes. This, in turn, required that the valve body be equipped with a threaded opening at some predetermined location thereon. Difficulties could arise in those situations where insufficient room was available on the body to accommodate the appropriate threaded opening.
Another known locking bracket is dimensioned for eliminating the problems associated with overhang. This known bracket is not, however, as easily and inexpensively manufactured as is desirable. Moreover, in this type of locking bracket, the fastener which secures the bracket to the valve body still requires cooperation with an aperture in the body. Again, the provision of such an aperture may be difficult in some valve bodies. Typical of these situations are where smaller or special valve bodies are involved which simply do not have a size or conformation to accommodate receipt of a separate mechanical fastener.
Accordingly, it has been considered desirable to develop a new and improved arrangement for locking a multi-sided member in a desired mounted relation relative to a rigid body. The subject invention overcomes the foregoing difficulties and others while providing better and more advantageous overall results.